The present invention concerns photographic cameras provided with electrooptic shutters, typically comprised of either liquid-crystal or else ferroelectric material. Such electrooptic diaphragms usually comprise a concentric arrangement of usually circular annular electrodes defining radially successive annular zones containing electrooptic material, and a control circuit is used to establish how many adjoining annular zones are to be rendered transparent, in order to thereby establish the size of the exposure aperture, either under automatic control in dependence upon measured scene light or else under manual selection.
It will be appreciated that camera diaphragms involving the use of moving mechanical parts are known in an enormous variety of designs and these are subject to a certain amount of frictional wear during use.
Likewise, it is known to provide a liquid-crystal electrooptic diaphragm comprised of radially overlapping annular liquid-crystal zones, involving the use of plural carrier structures, in order to avoid the establishment of intermediate zones between electrodes in which transparency cannot be controlled.